How To Proceed With Troubleshooting

WARNING: This page is about a different car, the 2008 Toyota FJ Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

DTCs for the CAN communication system are as follows: U0073, U0100, U0123, U0124 and U0126.
Refer to the troubleshooting section for each system if DTCs regarding the CAN communication system are not output.
Turn the ignition switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
After the ignition switch is turned off, check that the key reminder warning system is not in operation.
Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If doors need to be opened in order to check connectors, open the doors and leave them open.
HINT:

Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

CHECK CAN BUS LINE
1. Check CAN BUS LINE .
CHECK INSTALLED SYSTEMS (ECUs AND SENSORS) THAT ADOPT CAN COMMUNICATION
CHECK AND CLEAR DTCs

CHECK CAN COMMUNICATION USING TECHSTREAM VIA CAN VIM

Select "BUS CHECK" (See DIAGNOSIS SYSTEM ).

Result

RESULT TABLE

All ECUs and sensors connected to CAN communication system displayed on screen.	A
One ECU or sensor connected to CAN communication system not displayed on screen.	B
2 or more ECUs and sensors connected to CAN communication system not displayed on screen.	C

NOTE:

The systems (ECUs and sensors) that adopt CAN communication vary depending on the vehicle and option settings. Check which systems (ECUs and sensors) are installed on the vehicle (See DIAGNOSIS SYSTEM ).
Non-installed ECUs or sensors are not displayed. Do not mistake them for being in communication stop mode.
If 2 or more ECUs or sensors are not displayed on the Techstream via the CAN VIM, perform troubleshooting for an open in one side of the CAN bus line for each undisplayed ECU or sensor.

B: GO TO COMMUNICATION STOP MODE TABLE

C: GO TO OPEN IN ONE SIDE OF CAN BRANCH LINE

A: Go to next step.

DTC COMBINATION TABLE
1. Confirm trouble according to the combination of output DTCs regarding the CAN communication system.
  HINT:
  
  Previous CAN communication system DTCs may be the cause if CAN communication system DTCs are output and all ECUs and sensors connected to the CAN communication system are displayed on the Techstream's "BUS CHECK" screen via the CAN VIM.
INSPECT CIRCUIT
IDENTIFY PROBLEM
REPAIR OR REPLACE
PERFORM CONFIRMATION TEST
NEXT: END